PragmaticPhil
Published © GPL3+

Making card games on micro:bit, Part 2

Learn how to use micro:bit to show playing cards on an SSD1306 128x64 OLED display. A key element of any card game.

IntermediateFull instructions provided1 hour636
Making card games on micro:bit, Part 2

Things used in this project

Hardware components

BBC micro:bit board
BBC micro:bit board
Any SBC that you can code in MakeCode will do - check out the excellent Maker.MakeCode IDE and see the broad range of boards supported :)
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OD01
XinaBox OD01
We use an SSD1306 as the display. You can use a different type of screen or a differently mounted SSD1306 - the code should be easy to adapt
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XinaBox IM01 micro:bit bridge with microSD card support
We use persistent memory to ensure our graphics are visually appealing. 17 small (1kb) bitmaps are saved on microSD card and referenced in runtime. This works around limitations in micro:bit memory,
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XC10
XinaBox XC10
You only need 1 of these, to connect the OD01 to the IM01.
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Story

Read more

Schematics

Guide to 'public' functions

Review the functions that we developed in this project and how they fit together. There are only 2 functions that you need to use, as explained on this diagram

Lookup table

Each card in a standard deck is represented by an integer from 0 to 51 (called IntID). But convention: 0, 13, 26, 39 = Ace. +1 = two, +2 = three etc. 0-12 = hearts, 13-25 = Clubs etc. A lot of info is encoded into IntID - a lot of that info is shown in this lookup table

Code

Displaying playing cards on an SSD1306

JavaScript
Ignore the warnings below - load the extensions (OD01 and IM01) and it will be fine. You are better off using the shared project link: https://makecode.microbit.org/_LXx2PWCa2P1m
function drawCardFace (lateralPosition: number, faceID: number) {
    drawCardAsset(lateralPosition + 1, 40, IM01.readFile("face" + convertToText(faceID) + ".txt"))
}
function drawAsset (lateralPosition: number, height: number, bitmapString: string, imageWidth: number, imageHeight: number) {
    countColumns = 0
    countRows = 0
    for (let index = 0; index <= imageWidth * imageHeight - 1; index++) {
        if (bitmapString.charAt(index + 1) == "1") {
            OD01.pixel(lateralPosition + countColumns, height + countRows, 1)
        }
        countColumns += 1
        if (countColumns >= imageWidth) {
            countColumns = 0
            countRows += 1
        }
    }
}
input.onButtonPressed(Button.A, function () {
    OD01.clear()
    for (let index2 = 0; index2 <= 4; index2++) {
        basic.showNumber(index2)
        drawCard(getLateralDrawPosition(index2), playerHand[index2])
        OD01.showNumber(playerHand[index2], index2 * 26, 0, 1)
    }
    basic.showIcon(IconNames.Yes)
})
function shufflePack () {
    resetPack()
    for (let loopX = 0; loopX <= packSize - 1; loopX++) {
        cardChosen = randint(0, originPack.length - 1)
        deckOfCards.insertAt(loopX, originPack.removeAt(cardChosen))
    }
    activeCard_PackPosition = 0
    numberPackShuffles += 1
}
function getLateralDrawPosition (drawCardNumber: number) {
    if (drawCardNumber * 26 + 24 >= 128) {
        return drawCardNumber * 26 - 1
    }
    return drawCardNumber * 26
}
function getCardSuit (cardID: number) {
    return (cardID - getCardFaceID(cardID)) / 13
}
function drawBorder (lateralPosition: number) {
    OD01.rectangle(lateralPosition, 16, lateralPosition + 24, 63, 1)
}
function drawCard (lateralPosition: number, cardID: number) {
    drawCardFace(lateralPosition, getCardFaceID(cardID))
    drawSuit(lateralPosition, getCardSuit(cardID))
    drawBorder(lateralPosition)
}
function drawSuit (lateralPosition: number, suitID: number) {
    drawCardAsset(lateralPosition + 1, 17, IM01.readFile("suit" + convertToText(suitID) + ".txt"))
}
function getDealtCard () {
    if (activeCard_PackPosition >= 52) {
        shufflePack()
    }
    return deckOfCards[activeCard_PackPosition]
}
function resetPack () {
    originPack = [packSize]
    for (let loopX2 = 0; loopX2 <= packSize - 1; loopX2++) {
        originPack[loopX2] = loopX2
    }
}
input.onButtonPressed(Button.B, function () {
    startNewHand()
    basic.showNumber(handsPlayed)
    basic.showString("X")
    basic.showNumber(numberPackShuffles)
    basic.showIcon(IconNames.Yes)
})
function drawCardAsset (lateralPosition: number, height: number, bitmapString: string) {
    drawAsset(lateralPosition, height, bitmapString, 22, 22)
}
function startNewHand () {
    handsPlayed += 1
    playerHandSize = 0
    for (let index22 = 0; index22 <= 4; index22++) {
        playerHand[index22] = getDealtCard()
        activeCard_PackPosition += 1
        playerHandSize += 1
    }
}
function getCardFaceID (cardID: number) {
    return cardID % 13
}
let playerHandSize = 0
let numberPackShuffles = 0
let activeCard_PackPosition = 0
let originPack: number[] = []
let cardChosen = 0
let countRows = 0
let countColumns = 0
let playerHand: number[] = []
let deckOfCards: number[] = []
let packSize = 0
let handsPlayed = 0
let handsWon = 0
handsPlayed = 0
packSize = 52
let handMaxSize = 5
deckOfCards = [packSize]
playerHand = [handMaxSize]
shufflePack()
startNewHand()

Credits

PragmaticPhil

PragmaticPhil

9 projects • 16 followers
Pragmatic hobbyist

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